Process and Crucible Modification for Growth of High Doped 4H-SiC Crystal with Larger Diameter

The present research was focused to investigate various process parameters influenced on the large 4H-SiC crystal growth on a 6H-SiC seed by PVT method. The crucible diameter along horizontal axial direction and inserted graphite ring was modified to change the growth parameter like the temperature gradient. In the initial stage of growth, foreign polytypes such as 6H/4H were observed on 6H-SiC seed, indicating the growth temperature to be unstable on crystal surface. However, from the middle of growth step, 4H-SiC was successfully formed in the ingot with the modification of growth pressure and a SIMS analysis confirmed the high doping concentration in grown 4H-SiC crystal.